Network Classification, Components, and Protocols
Network Classification
Definition
A network is a system of interconnected devices that can communicate and share resources. Its objective is to facilitate information and resource sharing, making data and programs accessible to any authorized user on the network, regardless of their physical location.
Network Extension
- LAN (Local Area Network): Typically spans a single building or smaller area, commonly used in offices and facilities.
- MAN (Metropolitan Area Network): Covers a larger geographic area, such as a city.
- WAN (Wide Area Network): Connects networks across cities, countries, or even globally, often used by large organizations.
Network Topology
- Ring: Computers are connected in a closed loop. Data travels in one direction, and each computer checks if it is the intended recipient.
- Bus: All computers share a single communication cable (the bus). Terminators are placed at each end of the bus.
- Star: All computers connect to a central device (like a switch) that manages communication.
Network Components
Specifications
Network components are characterized by physical elements, spacing, speed, and protocols. Common standards include IEEE 802.3 (Ethernet), 802.11 (WiFi), 802.5 (IBM Token Ring), 802.6 (MAN), 802.15 (Bluetooth), and 802.16 (WiMax).
Transmission Media
- Guided Media:
- Twisted-pair cable (UTP and STP)
- Coaxial cable
- Fiber optic cable
- Unguided Media:
- WiFi
- Bluetooth
- Infrared
- Microwave
Twisted-pair cable: Consists of twisted copper wires to reduce interference.
Coaxial cable: Features a central copper core, insulator, and shielding for enhanced data protection.
Fiber optic cable: Transmits data as light pulses through thin glass or plastic fibers.
WiFi: Uses radio waves for wireless data transmission.
Bluetooth: A short-range wireless communication standard.
Infrared: Employs light rays in the infrared spectrum.
Microwave: Transmits data using microwaves, similar to radio technology.
Hardware Interconnection
- Network Adapter: Enables devices to connect to the network.
- Hub: A central connection point for devices in a star network.
- Switch: A more efficient alternative to a hub, directing traffic between devices.
- Router: Connects different networks and manages data routing.
- Modem: Allows computers to communicate over telephone lines.
Network Protocols
Definition
- Media Access Control (MAC) Protocols: Govern access to the physical medium (e.g., CSMA/CD).
- Application Protocols: Define how client and server applications interact (e.g., HTTP, FTP, SMTP).
- Communication Protocols: Set rules for communication between devices using different languages.
TCP/IP Protocol
TCP (Transmission Control Protocol): Establishes a connection for reliable data transmission.
IP (Internet Protocol): Provides addressing and routing for data packets. IP addresses (public and private) identify devices on the network.
IP Address Classes and Netmasks: Classes A, B, and C define different ranges of IP addresses and network sizes.
Routing Protocols
Routing Tables: Help routers determine the best path for data packets.
NAT (Network Address Translation): Maps private IP addresses to public IP addresses.
DNS (Domain Name System): Translates domain names (e.g., google.com) into IP addresses.
DHCP (Dynamic Host Configuration Protocol): Automatically assigns IP addresses and other network settings to devices.
Gateways and Proxy Servers: Act as intermediaries between networks. A proxy server can provide internet access to multiple devices behind a single public IP address.